Chris Traeger, the painfully cheerful health nut, is "LITRALLY" (This is an intentional misspelling; 'Parks' nerds spell it the way Chris says it.) the most enthusiastic person to ever set foot in Pawnee, Indiana. He delivers news in such a positive tone that even bad news comes across as good. At one point in season three, he even broke up with Ann Perkins (Rashida Jones, 'The Office') without her knowing they had broken up.
His over-the-top enthusiasm, paired with his ultra-health-conscious lifestyle (and the way that contrasts with Ron Swanson’s bacon-and-eggs-conscious lifestyle) make for one hilarious scene after another. Only Chris Traeger would play air banjo in the backseat to Ann’s anti-romance mix CD.